Tire filler



May 28, 1929. .1.l H. DALBl-:Y f 1,714,710

" y n TIRE FILLER v'Filed Sept. 13, 1926 JQM@ QW?? Patented May 28,1929. Y i

- vJAMES H. DALBEY, or Encan, ILLINOIS.

TIRE EILLER.

Application filed September 13, 1926. Serial No. 135,168.

This invention relates to improvements in fillers, for pneumatic tirecasings, which in use simulate the well known air tubes but which arenot subject to puncture or collapse.

This present invention has to do primarily with the production of aspongy rubber iiller in which the density of the material is so varied,or, in other words, the material is so distributed that the filler iseasier to install, which is less liable to break down or disintegrateunder the strains and distortions in use, and which is therefore moredurable than fillers heretofore made.

It is well known to make la yielding filler core or body which isadapted to be compressed within an ordinary pneumatic tire casing and soarranged that when installed it shall be compressed to al suitableextent to properly sustain the imposed load. Such cores or fillers areusually made of spongy rubber of a cross-sectional form or sectionadapted to properly fit within the, casing to be filled'and long enoughto completelyV fill the casing. Some forms of such cores have V-shapedslots along their inner sides which are adapted to be closed when thecore is compressed within a casing.

Heretofore, so far as I Vhave been made of substantially uniform densitythroughout and no attempt has been made to vary the density 4indifferent parts of the core or to so vary it as to make the installationof the core easier or to prevent the disintegration ofthe core in use.

A core of the form described has a crosssection which is roughly'cylindrical but es-y pecially shaped to properly fit within, fill`gether and together with the body portion compressed more or less whenthe core 1s *1n-v stalled within a casing.

. It is intended that the casing shall be held -distended by the fillerunder such a pressure frasfto best simulate the usual .pneumatic tube amaware, the cores p so as to prevent too great distortion of the casingor the tire as a whole when subjected to the load in use. Also Yit hasbeen found that the installation of a ller in a casing and the mountingof the filled casing on a suitable rim are not ations.

My present invention relates particularly to a construction of corewhich will be easier to apply than the cores heretofore made and whichwill absorb theapplied load within its capacity without"producingdisintegrating movements or pressures Within the core.

My invention Vconsists of acore or `filler of the character described inwhich there -is a variat-ionof the density or Aporosity of the core, thebody portion being more-dense or harder than the wing portions. Anotherfeatureis that the inner edges 'of the Wing portions are the softestportions and that the wing portions increase in density towardtiieV bodyportion.

Such cores or fillers are produced by means of a. ring mold of the shapeand size desired. y In this mold is placed a suitable quantity ofl rawrubber prepared for vulcanizing. vThis raw rubber has impregnatedtherein a suitable proportion of carbonate of ammoniaor particularlyeasy oper.

other suitable chemical `for rproducing the porosity ofthe core.. Theprepared rubber is first roughly Yrolled out to the shape of the mold.It is then enclosed in thefmold and the mold is heated to a vulcanizingtemperature. The heat is transmitted through the Wallsrof the mold,which is usually made of cast iron, to the lmass of rubberwithin .themold. The heating prod ucesla vgas from the carbonate of ammonia whichforms cells within'the rubber causing the rubber `to completely iill'themold, the heat also causingthe vulcanization lof the rubber in itsexpandedcondition, viz,

full ofl small gas cells, thus producing the spongy core or fillerdesired. -By allowing space lwithin the mold for'fone Ypart ofthe massof rubber to expand more than another, I am enabled to modify orvvaryth'edensity of the-*completed core.

H For the purpose of making the inner edges of the wing portions of thefiller softer' than the body portion the mass of raw rubber isformedroughly intoy the cross-sectional shape of the mold'but with thewingportions somewhatV shorter or less full than to completely v. v

fill thevving portions -of-'the mold; In'other.

words .voids or unii-lled spaces -are Ileft inthe mold into which therubber can be expanded when the carbonate of ammonia forms the gascells. Consequently in these portions of the which forms the two wings,with a relatively wide inner or bottom portion so that when the filleris properly mounted in a casing the inner portions of the walls of theslot, which are subject to more or less relative movement in the'swayingor sidewise distortion of the tire, do not contact with eachother,and consequently are not subjected to destructive disintegratingrelative movement. Y

My invention will Vbe more readily understood by vreference to theaccompanying drawings in which I have illustrated the improved method ofmanufacture and the improved filler which is the product of the method.i'

In said drawings z- Fig. 1, is a cross-sectional .View of a tire casingand rim with one of my improved fillers installed;

2. is a view similar to Fig. 1, illus trating the shape, the casing'andfiller as sumes when subjected to a load;

Fig. 3, 1s a cross-sectional view of the filler itself;

Fig. 4, is an enlarged fragmentary cross sectional view of one of thewing portions of the filler illustrating the internal structure of same;and

Fig. 5, is a cross-sectional view of a vulcanizing mold with a coretherein which has been vulcanized. 1

In said drawings 1 illustrates a tire casing such as is commonlyused inconnection with a pneumatic distended. The casing is shown as mountedfor use on. what known as a clincher tire rim 2. This rim adapted to bemounted and held upon a vehicle wheel for use. The rim, as shown, hasinturned 'lianges 3 atv its sides and the casing` 1 is, formed with rimV beat s l at the base of the casing, which are Vreceived within theiii-turned side flanges of the rim and by which the casing is held uponthe rim.

In place of the usual inner tube, which in a pneumatic tire is adapted`to hold air under pressure and thereby hold the casing properlvdistended, I provide a yielding iiller 5.

I The iiller 5 is preferably made of spongy rubber and in the process ofmanufacture raw rubber is vulcanized to produce Ythe size,

shape and form ofthe filler desired." The filler 5, as shown in Fig. 1,in which the tire is illustrated as ready for use, is compressed tubefor holding same properly to an amount whereby the casing is helddistended with sufiicient pressure to properly sustain the load withouttoo great distortion of thetire.

l Fig. 2, illustrateswhat may be termed the normal load distortion ofthe tire.

Fig. 8 shows a cross-sectional view of the filler 5 before it isinstalled in the casing 1. The filler i'sroughlv of horse-shoe shapehaving an outer part @which extends from about the middle of the fillerto the outer periphery and two wing like portions 7 extending ,from themiddle of the filler to the inner periphery. It should be understoodthat preferably the filler is made in a 'ring form` and of a size to litthe intended casing, also that the crosssectional area of the filler asshown in Fig. 3, is enough greater than they normal crossseetional areaof the ,hollowl space within the casing 1, thatV it is necessarytocompress the filler in mounting it within the casing and mounting thecasing upon the rim. This greater area ofthe filler is necessary so thatthe tire will properlyv sustain the imposed load without a too Oreatinitial distortion. The two wing portions 7 are separated by arelatively wide V-shaped groove or slot 8 which entends from the middlepart of the .filler to the inner periphery and which eX- tendscircun'iferentially around the filler. This slot- 8 is preferably fairlywide at its bottom or inner end 9 for a purpose to be described. v

As shown in Fig. 1, the filler when installed is somewhat pear shapedthe wing portions 7 being pressed tightly together and filling inbetween the casing beads 4. The casing beads l are convex on their innersurfaces as shown at 10 and as they are much harderthan the filler theycompress the wings into the shape shown. lhen the filler rhas beenplaced in a casing the beads 4 are held spread apart by the wingportions 'l' and in mountingthe tire on a rim it is necessaryY inneredge vportions 11 being lmade with larger gas'pockets 12 than the otherparts of the filler. As illustrated the density increases from the inneredges of the Wing parts 7 toward the center and as shown in Fig. 3, thedensity of the filler decreases from the middle portion l13 toward theouter periphery.

In manufacturing fillers'of the kind described the raw rubber or rubbermixture is first `prepared in lthe usual manner by means of'rolls, themass having mixed therein lli a suitable proportion of a carbonateprefer- After the mass has been properly prepared it is forced by greatpressure through adie opening of a shape similar to the cross-sectionalshape of the finished filler except thatv as indicated by the dottedlines 14C the inner edges of the wing portions 7 do not completely lillthese parts of the mold 15.

The .mold 15 is preferably two half rings 16 adapted to be boltedtogether upon a median plane and the inner part of the mold is madek ofa ring 17 having an outer circumferential y part 18 which is adaptedtoproduce the slot lil S in the filler.

As explained the prepared raw filler is so formed that free spaces 20are left in the mold into which the inner end portions 11 Aof the fillercan expand in the vulcanizing process. As there is very slight shiftingof the body of the material while being vulcanized the result is thatthe inner parts 11 of the wing portions 7 are more porous or moreyielding thanV the other parts of the filler.

As they heat is applied to the iiller through the walls of the mold theheat reaches the outer parts of the mass first and actsupon thecarbonate slightly in advance of acting upon the carbonate furtherWithin the mass with the result that the outer portions of the fillerare softer than thecenter portions. This latter holds true except thatthe ring'l carries the heat quickly into the center of the mass with theresult that surrounding the part 18 of the ring isk a section or layervof the .filler which is more yielding thanthe main body portion. VAsshown in Fig; 1, when the filler is installed for use the whole filleris vcompressed y and the wings 7 are forced tightly together except atthe inner end 9 of the slot 8, which has been purposely made' wide toprevent close contact atthis point. The inner edges 11 of the wings 7being` relatively soft permit them tobe readily compressed and'distorted as indicated in Fig. 41. V y

Tn use under an imposed load as illustrated in Fig; 2, the main body ofthe filler being relatively harder than the lother portions is l notdistorted to a. great extent but is Vforced bodily inward andat the sametime expanded laterally. In this` distortion the wing portions 7 areconsiderably compressed radially and spread out laterally, the innerend` 9 of' the slot 8 being enlarged as shown and separating'the sidewalls ofthe slot from the inner end9 thereof towards the rim. This. A

separation of the side walls ofthe slot una der a working load preventsor eliminates the rubbing` of one surface onthe other'and thuseliminates all destructive abrasion and fricf` tion which has been theprincipal detrimentall feature of such fillers heretofore made and used.z

The density of the wing portions as indicated gradually increases fromtheir inner 2 i i edges 11 toward the middle of thefiller and likewisethe density of the filler itself increases from its outer surfacevtoward the vmiddle portion thereof. This construction resultsin thesofter more compressible inner edges of the wingsand also in a'relativelyl softer outer portion in contactvwith the casing and incondition to best adapt itself to proper contact with the casing.

As' many modifications ofrthis invention will lreadily suggestthemselves toene skilled vin the art Tdo not limit my invention to thespecific details of the improved method or the structure'ofthe fillerexcept within the scope of the appended claims. f Tclaiin:V 11A spongyrubber filler for use in a tire casing,

` the filler having a v'circumfe'rential outer body portion and having acircumferx ential slot at its inner side dividing thefinnery partfof thefiller into two wing-like portions which extend inwardly from the bodyportion,the body portion being more dense than the wing portions. n

2. A spongy rubber filler for use in a tire casing, the iiller having acircumferential outer body portion and having a circumferenl tial slotat its inner side dividingthe inner part of the filler into twowing-like portions which extend inwardly from the bodyportion, the wingportions having larger cells than the body portion and which cellsinportions.

3. A spongy rubber filler for use in la tire casing, theV filler havinga circumferentlal parts of the'wing portions having relatively large`cells and consequently being relatively y crease in size toward thetips of the wing-like soft, ythe wings increasing in density toward tthe body portion and the bodyvport-ion being more dense than Ythe wingportions. i

i In testimony whereof, I have hereunto setv my hand, this llth-dayofSeptember, 1926.v

JAMES' H. DAL'BEY.

